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Wahlström, N., Harrysson, H., Undeland, I. & Edlund, U. (2018). A Strategy for the Sequential Recovery of Biomacromolecules from Red Macroalgae Porphyra umbilicalis Kützing. Industrial & Engineering Chemistry Research, 57(1), 42-53
Open this publication in new window or tab >>A Strategy for the Sequential Recovery of Biomacromolecules from Red Macroalgae Porphyra umbilicalis Kützing
2018 (English)In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 57, no 1, p. 42-53Article in journal (Refereed) Published
Abstract [en]

A nondestructive, multicomponent fractionation strategy has been developed to extract proteins and polysaccharides from the red macroalgae Porphyra umbilicalis collected along the west coast of Sweden and cultivated indoors under controlled conditions. First, a protein-rich fraction was extracted in an ice-cold alkaline solution. The overall protein content in Porphyra umbilicalis was estimated to be 30.6% of the dry weight, and out of that, 15.0% could be recovered. Water-soluble polysaccharides were then extracted from the insoluble residual fraction using sequential alkaline and acidic treatments at 90 °C for 4 h. Spectroscopic and chromatographic analyses of the polysaccharide fractions show that high-molecular-weight carrageenans were obtained from the alkaline extraction and a galactose-rich pectin substance was obtained from the acidic extraction. The insoluble fraction remaining after all extraction steps was rich in cellulose. An elemental analysis of Porphyra umbilicalis via scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM-EDS) showed the presence of C, O, Na, Ca, Mg, Al, Cl, and S. However, no heavy metals or other toxic elements, such as Pb, Hg, and As, were found.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-221687 (URN)10.1021/acs.iecr.7b03768 (DOI)000419999800003 ()2-s2.0-85040457542 (Scopus ID)
Note

QC 20180122

Available from: 2018-01-22 Created: 2018-01-22 Last updated: 2018-02-02Bibliographically approved
Sterner, M. & Edlund, U. (2018). High-Performance Filaments from Fractionated Alginate by Polyvalent Cross-Linking: A Theoretical and Practical Approach. Biomacromolecules, 19(8), 3311-3330
Open this publication in new window or tab >>High-Performance Filaments from Fractionated Alginate by Polyvalent Cross-Linking: A Theoretical and Practical Approach
2018 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 19, no 8, p. 3311-3330Article in journal (Refereed) Published
Abstract [en]

A series of alginate fractions with significant differences in molecular weight and uronic acid compositions were produced by consecutive fractionation and converted to thin and strong cross-linked polymer filaments via extrusion into calcium, aluminum, or polyaluminum (PolyAl) polyvalent solutions followed by drawing and drying. Models were elaborated to relate the alginate uronic acid composition to the tensile performance in both the wet gel filament and the dry filament states. The wet gel model was compared to the theory of the unidirectional elongation of charged polyelectrolyte gels based on the classical rubber elasticity of dilated polymer networks, extended to include the contributions of non-Gaussian chain extensions and the effect of electrostatic interactions. The theory of equilibrium swelling pressure was applied to describe the observed shrinkage of the alginate gels following immersion in a polyvalent solution. Congruent with the theoretical model of charged gels, the tensile performance of the gel filaments prepared from CaCl2 depended on the compositional ratio of guluronic acid dyads in the alginate fraction multiplied by the alginate concentration, while the tensile behavior of wet gel filaments prepared by AlCl3 instead resembled that of elastic solid materials and depended only on the alginate concentration. The dry filament tensile properties were greatly dependent on the preparation conditions, particularly the ratio of stress to alginate concentration and the nature of the ions present during filament drawing. The PolyAl solution effectively caused shrinkage of alginate to a strong extent, and the resulting filaments behaved as highly stiff materials able to withstand stresses of approximately 500 MPa and having elastic moduli as high as 28 GPa.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-234196 (URN)10.1021/acs.biomac.8b00619 (DOI)000441852400015 ()29954171 (PubMedID)2-s2.0-85049409145 (Scopus ID)
Note

QC 20180911

Available from: 2018-09-11 Created: 2018-09-11 Last updated: 2018-11-20Bibliographically approved
Svärd, A., Brännvall, E. & Edlund, U. (2018). Modified and thermoplastic rapeseed straw xylan: A renewable additive in PCL biocomposites. Industrial crops and products (Print), 119, 73-82
Open this publication in new window or tab >>Modified and thermoplastic rapeseed straw xylan: A renewable additive in PCL biocomposites
2018 (English)In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 119, p. 73-82Article in journal (Refereed) Published
Abstract [en]

Xylan extracted from rapeseed straw was chemically modified to gain hydrophobic and thermoplastic properties via macroinitiator formation followed by a free radical grafting-from polymerization with octadecyl acrylate. Biocomposites were then prepared by incorporation of 5 or 20% (w/w) rapeseed straw xylan into a poly(epsilon-caprolactone) (PCL) matrix by melt extrusion. The grafted xylan was homogeneously distributed within the biocomposite and reinforced the PCL matrix while at the same time preserving the ability to elongate to tensile strains > 500%. Analogous biocomposites made from unmodified xylan in a PCL matrix resulted in heterogeneous mixtures and brittle tensile properties.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Biocomposite, Grafting, Hemicellulose, Rapeseed/canola straw, Thermoplastic, Xylan
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-227505 (URN)10.1016/j.indcrop.2018.03.067 (DOI)000432763800009 ()2-s2.0-85045072624 (Scopus ID)
Funder
Swedish Research Council Formas, 2013-844
Note

QC 20180518

Available from: 2018-05-18 Created: 2018-05-18 Last updated: 2018-09-07Bibliographically approved
Choong, F. X., Back, M., Schulz, A., Nilsson, K. P., Edlund, U. & Richter-Dahlfors, A. (2018). Stereochemical identification of glucans by oligothiophenes enables cellulose anatomical mapping in plant tissues. Scientific Reports, 8, Article ID 3108.
Open this publication in new window or tab >>Stereochemical identification of glucans by oligothiophenes enables cellulose anatomical mapping in plant tissues
Show others...
2018 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 3108Article in journal (Refereed) Published
Abstract [en]

Efficient use of plant-derived materials requires enabling technologies for non-disruptive composition analysis. The ability to identify and spatially locate polysaccharides in native plant tissues is difficult but essential. Here, we develop an optical method for cellulose identification using the structure-responsive, heptameric oligothiophene h-FTAA as molecular fluorophore. Spectrophotometric analysis of h-FTAA interacting with closely related glucans revealed an exceptional specificity for beta-linked glucans. This optical, non-disruptive method for stereochemical differentiation of glycosidic linkages was next used for in situ composition analysis in plants. Multi-laser/multi-detector analysis developed herein revealed spatial localization of cellulose and structural cell wall features such as plasmodesmata and perforated sieve plates of the phloem. Simultaneous imaging of intrinsically fluorescent components revealed the spatial relationship between cell walls and other organelles, such as chloroplasts and lignified annular thickenings of the trachea, with precision at the sub-cellular scale. Our non-destructive method for cellulose identification lays the foundation for the emergence of anatomical maps of the chemical constituents in plant tissues. This rapid and versatile method will likely benefit the plant science research fields and may serve the biorefinery industry as reporter for feedstock optimization as well as in-line monitoring of cellulose reactions during standard operations.

Place, publisher, year, edition, pages
NATURE PUBLISHING GROUP, 2018
National Category
Plant Biotechnology
Identifiers
urn:nbn:se:kth:diva-225306 (URN)10.1038/s41598-018-21466-y (DOI)000425190500012 ()29449697 (PubMedID)2-s2.0-85042212769 (Scopus ID)
Note

QC 20180404

Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-05-24Bibliographically approved
Sterner, M., Ribeiro, M. S., Gröndahl, F. & Edlund, U. (2017). Cyclic fractionation process for Saccharina latissima using aqueous chelator and ion exchange resin. Journal of Applied Phycology, 29(6), 3175-3189
Open this publication in new window or tab >>Cyclic fractionation process for Saccharina latissima using aqueous chelator and ion exchange resin
2017 (English)In: Journal of Applied Phycology, ISSN 0921-8971, E-ISSN 1573-5176, Vol. 29, no 6, p. 3175-3189Article in journal (Refereed) Published
Abstract [en]

A new approach to process Saccharina latissima algal biomass was developed using sodium citrate and a polyvalent cation-specific resin to sequentially extract the alginate into several usable fractions. The fractionation was performed in a cyclic manner, utilizing a stepwise removal of the native polyvalent ions present in the algae to isolate fractions of alginate with different solubility in the presence of these ions. Sodium citrate was used in different concentrations in the extraction solution to remove polyvalent cations to adjust the alginate liberation while AMBERLITE IRC718 resin was added to further remove these ions and regenerate the extraction solution. Alginate was recovered by acid precipitation and analyzed for its uronic acid composition and molecular weight, and the carbohydrate compositions of the insoluble and soluble parts of the algal biomass residue were determined. Finally, the fractionation method was assessed with a life cycle analysis to determine the energy and water efficiency as well as the greenhouse gas emissions and the results were compared to conventional alkaline extraction. The results indicate that the energy and water use as well as the emissions are considerably lower for the cyclic extraction in comparison with the conventional methods.

Keywords
Extraction, Fractionation, Alginate, Saccharina latissima, Phaeophyceae, Chelation, Ion exchange resin
National Category
Biological Sciences
Identifiers
urn:nbn:se:kth:diva-220268 (URN)10.1007/s10811-017-1176-5 (DOI)000416446400042 ()2-s2.0-85020641776 (Scopus ID)
Note

QC 20180111

Available from: 2018-01-11 Created: 2018-01-11 Last updated: 2018-11-20Bibliographically approved
Svärd, A., Brännvall, E. & Edlund, U. (2017). Rapeseed straw polymeric hemicelluloses obtained by extraction methods based on severity factor. INDUSTRIAL CROPS AND PRODUCTS, 95, 305-315
Open this publication in new window or tab >>Rapeseed straw polymeric hemicelluloses obtained by extraction methods based on severity factor
2017 (English)In: INDUSTRIAL CROPS AND PRODUCTS, ISSN 0926-6690, Vol. 95, p. 305-315Article in journal (Refereed) Published
Abstract [en]

Rapeseed straw consists of a hard epidermis that is rich in hemicellulose and lignin and a sponge-like interior that consists mainly of cellulose. The stems were subjected to water, alkali or acid as extraction medium. The effects of the extraction conditions were quantified using severity factors and by comparing the effects of different extraction pHs, temperatures and times. Extraction with alkali resulted in a higher yield, 47 g/100 g straw in, compared to water, 6 g/100 g straw in, or an acidic, 5 g/100 g straw in, extraction process. An increase in temperature improved the extraction yield; in particular, more xylan was extracted at an elevated temperature and higher alkalinity. However, at high alkalinity, increased extraction temperatures led to a reduction in the recovery of glucomannan. The highest molecular weights (similar to 35,000 g/mol) of the extracted hemicelluloses were obtained using extraction procedures with 1.5 M NaOH at 110 degrees C and autohydrolysis at 150 degrees C. While these two parameter settings had very similar severity factors, extraction under basic conditions afforded an extract rich in xylan and low in lignin content, whereas autohydrolysis generated a glucomannan-rich extract.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Rapeseed/canola straw, Extraction, Autohydrolysis, Severity factor, Hemicellulose
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-200198 (URN)10.1016/j.indcrop.2016.10.038 (DOI)000390621600035 ()2-s2.0-85004143297 (Scopus ID)
Note

QC 20170202

Available from: 2017-02-02 Created: 2017-01-23 Last updated: 2018-09-07Bibliographically approved
Galkin, M. V., Di Francesco, D., Edlund, U. & Samec, J. S. M. (2017). Sustainable sources need reliable standards. Faraday discussions (Online), 202, 281-301
Open this publication in new window or tab >>Sustainable sources need reliable standards
2017 (English)In: Faraday discussions (Online), ISSN 1359-6640, E-ISSN 1364-5498, Vol. 202, p. 281-301Article in journal (Refereed) Published
Abstract [en]

This review discusses the challenges within the research area of modern biomass fractionation and valorization. The current pulping industry focuses on pulp production and the resulting cellulose fiber. Hemicellulose and lignin are handled as low value streams for process heat and the regeneration of process chemicals. The paper and pulp industry have therefore developed analytical techniques to evaluate the cellulose fiber, while the other fractions are given a low priority. In a strive to also use the hemicellulose and lignin fractions of lignocellulosic biomass, moving towards a biorefining concept, there are severe shortcomings with the current pulping techniques and also in the analysis of the biomass. Lately, new fractionation techniques have emerged which valorize a larger extent of the lignocellulosic biomass. This progress has disclosed the shortcomings in the analysis of mainly the hemicellulose and lignin structure and properties. To move the research field forward, analytical tools for both the raw material, targeting all the wood components, and the generated fractions, as well as standardized methods for evaluating and reporting yields are desired. At the end of this review, a discourse on how such standardizations can be implemented is given.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2017
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-215459 (URN)10.1039/c7fd00046d (DOI)000411412300017 ()28671698 (PubMedID)2-s2.0-85029852504 (Scopus ID)
Note

QC 20171018

Available from: 2017-10-18 Created: 2017-10-18 Last updated: 2017-10-18Bibliographically approved
Maleki, L., Edlund, U. & Albertsson, A.-C. (2017). Synthesis of full interpenetrating hemicellulose hydrogel networks. Carbohydrate Polymers, 170, 254-263
Open this publication in new window or tab >>Synthesis of full interpenetrating hemicellulose hydrogel networks
2017 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 170, p. 254-263Article in journal (Refereed) Published
Abstract [en]

Two methods with different cross-linking mechanisms for designing hemicellulose-based full interpenetrating polymer networks (IPNs) were developed through the sequential synthesis of full IPNs from O-acetyl-galactoglucomannan (AcGGM) utilizing free-radical polymerization and a thiol-ene click reaction. A faster swelling rate was observed for all IPN formulations compared with the single-network gels. The highly porous structure of the IPNs with small interconnected pores was verified using scanning electron microscopy. A rheological analysis revealed that the AcGGM IPNs fabricated by the free-radical polymerization of acrylamide and N-N'-methylenebisacrylamide (cross-linker) had shear storage modulus (G') values approximately 5 and 2.5 times higher than that of the corresponding precursor single networks of AcGGM. IPNs achieved through thiol-ene reactions between thiolated AcGGM and polyethylene glycol diacrylate had G' values 35-40 times higher than the single-network reference hydrogels.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Interpenetrating polymer networks, Hemicellulose, Shear modulus, Hydrogel
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-210451 (URN)10.1016/j.carbpol.2017.04.091 (DOI)000402942900030 ()28521995 (PubMedID)2-s2.0-85018348714 (Scopus ID)
Funder
Swedish Research Council Formas, 2011-1542
Note

QC 20170706

Available from: 2017-07-06 Created: 2017-07-06 Last updated: 2017-07-06Bibliographically approved
Gamiz Gonzalez, M. A., Edlund, U., Vidaurre, A. & Gomez Ribelles, J. L. (2017). Synthesis of highly swellable hydrogels of water-soluble carboxymethyl chitosan and poly(ethylene glycol). Polymer international, 66(11), 1624-1632
Open this publication in new window or tab >>Synthesis of highly swellable hydrogels of water-soluble carboxymethyl chitosan and poly(ethylene glycol)
2017 (English)In: Polymer international, ISSN 0959-8103, E-ISSN 1097-0126, Vol. 66, no 11, p. 1624-1632Article in journal (Refereed) Published
Abstract [en]

Highly swellable hydrogels were produced by crosslinking of high molecular weight carboxymethylated chitosan (CmCHT) with poly(ethylene glycol) (PEG) oligomers. The hydrogel swelling capacity could be controlled via the crosslinking density and ranged from 900% to 5600%. The hydrogels showed good homogeneity with a high interconnected porosity in the swollen state and with nanodomains rich in CmCHT and others rich in PEG diglycidyl ether. Oscillatory frequency sweep analysis showed a storage modulus of 27kPa for the hydrogel with the highest crosslinking density, which together with the exhibited enzyme degradability with lysozyme at 59days indicate that these hydrogels have potential use in delivery systems or soft tissue regeneration. 

Place, publisher, year, edition, pages
WILEY, 2017
Keywords
carboxymethyl chitosan, poly(ethylene glycol) diglycidyl ether, swellable hydrogels, thermal analysis, rheological properties, degradation, citotoxicity assay
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-215776 (URN)10.1002/pi.5424 (DOI)000412166000025 ()2-s2.0-85030480744 (Scopus ID)
Note

QC 20171023

Available from: 2017-10-23 Created: 2017-10-23 Last updated: 2017-10-23Bibliographically approved
Ibn Yaich, A., Edlund, U. & Albertsson, A.-C. (2017). Transfer of Biomatrix/Wood Cell Interactions to Hemicellulose-Based Materials to Control Water Interaction. Chemical Reviews, 117(12), 8177-8207
Open this publication in new window or tab >>Transfer of Biomatrix/Wood Cell Interactions to Hemicellulose-Based Materials to Control Water Interaction
2017 (English)In: Chemical Reviews, ISSN 0009-2665, E-ISSN 1520-6890, Vol. 117, no 12, p. 8177-8207Article, review/survey (Refereed) Published
Abstract [en]

The family of hemicelluloses stands out as a very promising natural resource that can be utilized as a biobased materials feedstock. An in-depth understanding of the hemicellulose inherent structural and property features as well as the structure property relationships induced by the specific supramolecular hierarchical organization of lignocellulosic biopolymers will be a key enabling technology in the emerging biorefinery sector. This Review aims to give a perspective on these issues and demonstrate how the transfer of molecular wood cell interactions into hemicellulose-based materials may offer new design principles for material formulations.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2017
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-211393 (URN)10.1021/acs.chemrev.6b00841 (DOI)000404806000012 ()28581716 (PubMedID)2-s2.0-85021646195 (Scopus ID)
Note

QC 20170801

Available from: 2017-08-01 Created: 2017-08-01 Last updated: 2017-08-01Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-1631-1781

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